Current interrupting device



Nov. 12, 1963 'A @BATES ETAL 3,110,782

CURRENT INTERRUPTING DEVICE original Filed Nov. 18, 1959 2 Sheets-Sheet 1 INVENTORS 7eme/,e c, .5476s Nov. 12, 1963 A. c. BATES ETAL CURRENT INTERRUPTING DEVICE originalFiled Nov. 18, 1959 2 Sheets-Sheet 2 .r E. E;

United States Patent O 3,110,782 CUNT INTERRUPTING DEVICE Arthur C. Bates and Charles Reynolds Huttinger, Greensburg, Pa., assignors to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Original application Nov. 18, 1959, Ser. No. 853,881. Divided and this application Apr. 11, 1961, Ser. No.

9 Claims. (Cl. 200--78) This application is a division of our copending application, Serial No. 853,881, led November 18, 1959, in the names of Arthur C. Bates and Charles Reynolds Huttinger, entitled Current Interrupting Device and assigned to the assignee of the instant invention.

This invention relates to current interrupters in general and more particularly to current interrupters adapted to be operated in coordination with high voltage disconnect switches.

It is well known in the prior art that electrical currents in the range of from 50 to 600 amperes at voltages in excess of 2,500 volts can be interrupted in a confine-d annular space suitably arranged with arcing contacts and formed by a plunger moving axially in a tube at high velocity. Unless special precautions are taken in interruptersof this type the heat of lthe arc erodes portions of the interrupting chamber unevenly so that successive arcs tend to occur at the same location in the chamber accentuating local area erosion and considerably reducing the length of life for the interrupter and also reducing the degree of performance upon successive operations.

'In U.S. Patent 2,352,556, issued June 27, 1944 in the name of G. A. Matthews, entitled Apparatus for Protecting Power Lines, a coil is provided which generates a magnetic field operatively positioned to spin the arc in the interrupting chamber so erosion is evenly distributed. Lln the aforesaid patent the so-called spinner coil is connected in series between a substantially continuous current carrying contact and a stationary arcing contact.

In the interrupter of the instant invention there is provided but a single stationary contact. A spinner coil is included which is wound about the single stationary contact with the inner end of the coil being connected to the stationary contact and the outer end of the coil being connected to the external circuit.

The stationary contact is a ring-like member which receives the movable contact through the central opening thereof. Because of fthe close clearance between the outer surface of the movable contact and the inner surface of the stationary contact, variations in dimensional tolerances and minor misalignment assure that engagement is made between the contacts. At irst glance, the engagement between the contacts would appear to be inadequate from an electrical standpoint. iHowever, extensive testing has shown that this type of contact is imminently suitable and reliable -for the application in question.

In U.S. Patent 2,824,935, issued February 25, 1958, in the name of P. M. Haslam, entitled Interrupter Attachment for Disconnect Switc and assigned to the assignee of the instant invention, there is illustrated an operating mechanism for imparting a fast acting straight line motion to a plunger-like rod which carries the movable contact. The interrupter of the instant invention includes an operating mechanism yfor the movable contact which is superior in operation to the mechanism of the aforesaid Patent 2,824,935 and represents a simplified less expensive construction.

Briefly, this is achieved by winding a torsion spring and tripping a restraining latch when desired torque is "lee obtained. The spring torque is transmitted through a straight line motion linkage to the contact carrying rod to impart high velocity movement thereto. The loading of the spring and release of the energy stored therein is brought about in essentially the same manner for both opening and closing of the interrupters.

Accordingly, a primary object of the instant invention is to provide a novel current interrupting device adapted for operation in conjunction wi-th a high voltage disconnect switch.

Another object is to provide a current interrupting device including a novel spinner coil arrangement whereby only a single stationary contact is required.

Still another object is to provide an interrupting device in which one of the cooperating contacts is received by an opening in Ithe other cooperating contact with engagement being achieved solely through variations in dimensional tolerances and minor misalignment.

A further object is to provide an interrupting device having ya novel operating mechanism including a torsion spring and restraining latch means to impart a snap acting movement to the movable contact for both opening and closing of the interrupter devices.

These as well as other objects of the instant invention shall become readily apparent after reading the following description of the accompanying drawings in which: FIGURE l is a side elevation of the circuit interrupting device with portions of the housing broken away to reveal Ithe internal mechanism which is in the switch openv position.

FIGURE 2 is an end view of the interrupting device of FIGURE 1 looking in the direction of arrows 2-2.

FIGURE 3 is a side elevation of the interrupting device operating mechanism in the switch closed position.

.FIGURE 4 is an exploded perspective view of the operating mechanism.

FIGURE 5- is a perspective view of the stationary contact and spinner coil.

Now referring to the figures, interruptor 1t)l includes Y an upper metallic housing 11 for operating mechanism 12 and a lower metallic housing 13. Hollow insulator 14 is provided with ring members 15, 16 secured at opposite ends .thereof by means well known to the art. Screw means 17, passing through clearance openings in ring 15 and received by threaded apertures at the lower end of housing 11, secure housing 11 to the upper end of insulator 14. Screw means 18 passing through clearance openings in housingy 13 are received by threaded apertures of ring 16 to thereby secure housing 13 to insulator 14.

Operating mechanism 12, as will -be hereinafter explained in detail, is constructed to provide a high velocity motion to conducting rod 21 which is secured lat the upper end thereof to mechanism 12 at pin 22. Movable contact means 23 is secured to the lower end of rod 21 and is provided with a region larger in diameter than rod 21 to yform movable contact 24. Substantially all of rod 21 positioned above contact 24 is disposed within insulating sleeve 25 preferably constructed of Teflon. Teflon follower rod 26, of substantially the same outer diameter as insulating sleeve 25, is secured to the lower end of contact 24. The outer diameter of contact 24 is slightly greater than the outside diameter of follower rod 26.

. Running substantially the full llength of and disposed within insulator 14 is a Teon interrupting chamber liner 28 disposed in a thin walled insulating tube 29. At the lo/wer end of insulator 14 is a recess containing spinner coil assembly 30 (FIGURE 5). Assembly 30 comprises a ring-like stationary contact 31 preferably constructed of tungsten silver alloy. Spinner coil 32, wound about the outside of contact 31, is comprised of insulation covered thincopper ribbon with the inner end of the ribbon being secured to the outer surface of contact 31 and the outer end of the ribbon being in intimate contact with ring 16 at the lower end of insulator 14.

The two faces of coil assembly 30 are protected by Teon washers 33, 34. Threaded clamping bushing 35 retains elements V28--34 in their operative positions. Support and muler 36 is secured by screw means 37 to the lower end of housing 13 to provide a closure therefore.

.The electrical circuit through internupter 10 in the closed position thereof is from support 36, housing 13, and ring 16 to the outside turn of spinner coil 32, through coil 32 and stationary contact 31, movable Contact 24, conducting rod 21, pin 2,2, through linkages of operating mechanism y12 and through upper housing 111 to the external operating handle 38.

As interrupter 19 is opened an arc is drawn between contacts 24 and 3d in the restricted annular space 4t) between rod 26 and the sleevealike interrupter chamber liner 2S. The arc, being the same as a current carrying con'- ductor, is acted upon by the magnetic iield associated with spinner coil `32 which causes the arc to rotate in annular space 40. Thus, the ends of the arc constantly assume diiferent positions vat contacts 24, 3d and the intermediate portion of the arc is continuously being moved to different portions of space 40. Because of this there is a reduced loss of metal, erosion of the interrupter elements takes place uniformly, and in general there is a suppression of effects which are contrary to good interruption performance.

It should be noted that interrupter 10 when operated in conjunction with a disconnect switch does not carry any current in the closed position thereof since interrupter 10 is only Vtemporarily connected in series with the disconnect switch dur-ing the opening cycle thereof. Since this arrangement avoids the possibility of damage due to fault currents, the fact has been given due consideration in the switch construction hereinbefore described.

Operating mechanism 12 includes a main shaft 51 journalled in suitable bearings carried by upper housing 11. Operating handle 3S is keyed to shaft 51 together with latch release member 53. Members 54, 55 each pivotally mounted at the upper ends thereof to pin 56 extending inwardly from housing 11 include latch rollers 58, 59, respectively, at the lower end thereof. Torsion spring -7, positioned about pin 56, urges latch arms 54, 55 in such directions that latch rollers 58, '59 tend to converge.

In the open position of internupter llatch member 512 and roller 59 is biased against edge 61 of member 5-2. IIn the closed position of interrupter yit) latch roller 59 is disposed within detent 62 of member 52 and roller 58 is biased against edge 63 of member 52.

Latch member 52 is formed integrally with U-shaped link 65 which is freely mounted upon shaft 51. Torsion spring 66 is mounted upon sleeve 67 concentric with shaft 5d and positioned between the arms of link 65. One end 66 of spring 66 is positioned for engagement with extension 69 of link 65 and also with pin 7&1 which is radially extending from shaft 51. The other end 71 of spring 66 is positioned for engagement with extension 72 of link 65 as Well as with yextension 73 formed integrally with latch release member 53.

The free ends of link 65 are inwardly extending and are joined by pin 7 4 which provides an operative connection with link means 75 at a point intermediate the ends thereof. One end of link means 7f5 is secured by pin 22 to conducting rod 21 upon which movable contact 23 is mounted. The other end of link means 75- is pivotally mounted at 76 to journalling member 77. (Transverse aperture 78 extending through member 77 receives pin 79 secured to housing 11 and extending at right angles to shaft 51.

Interrupter 10 is operated from the open position of FIGURE l to the closed position of FIGURE 3 by a clockwise rotation of external ope-rating handle 38. lnitial movement of handle 38 in a clockwise direction between the positions of IFIGURES 1 and 3 results in a loading of torsion spring 66. Loading is brought about by the clockwise movement of spring end 7'1 through its engagement with latch release means extension 73 and the fact that spring end I68 abuts link extension 69 and at this time link 65 is restrained against rotation through the cooperation of ylatch roller 58 and latch member 52. At a pre-determined point in the movement of handle 38 toward the position occupied in FIGURE 3, latch release member 53 will have been rotated clockwise a suiiicient distance whereby latch release member 53 will have cammed roller 58 out of detent 60 over edge 63 of latch member 52. Thus, link 65 is no longer restrained and torsion spring 66 causes Ia snap-acting clockwise rotation of link 65.

Clockwise rotation of link 65 causes pin 74 to move downward causing counterolockwise rotation of link 75 about member 77. .lournalling means comprising member 77 and pin '79 at ther-ight hand end of link 75 coopcrates with pin 74 to impart a downward movement to conducting rod 21.

Housing formation 8d engaged by link means 75 establ-ishes the positional limits for the elements of mechanism 1=2 in the closed position of interrupter 10.

A similar operation takes place when interruptor ,iti is operated from the closed position of :FIGURE 3 to the open position of IFIGURE l. Initial movement of handle 5S in the counter-clockwise direction causes counter-clockwise rotation of pin 70 which engages spring end 68 for loading of spring 66 while spring end 711 is restrained against movement through its engagement with extension 72 of link 65. During this interval, link 65 is restrained against movement through the cooperation of the latch roller 5% and latch member 52. When shaft 51 reaches a predetermined angular position, latch roller 59 is cammed out of detent `62 over edge61 so that link 65 is no longer restrained and is free to move through the urging of spring 66. In this manner spring 66 imparts a high velocity snap-acting opening motion to conducting rod 21. Pin 39, extending across housing 11, is engaged by link 65 thereby establishing operational limits for the elements of mechanism 12 in the open position of interrupter 10.

Thus, We have provided a novel interrupter switch having ian operating mechanism of simplified construction and an arc interrupting means which effectively prevents localized erosion thereby increasing switch life.

Although we have here described preferred embodiment of our novel invention, many variations and modifications will now be apparent to those skilled in the art, and we therefore prefer to be limited, not by the specific disclosure herein, but only by the appending claims.

We claim:

l. A cirouitinterrupter including -a stationary contact, a movable contact, .and an operating mechanism means interconnecting said operating mechanism to said movable contact for moving said movable contact into and out of engagement with said stationary contact; said operating mechanism comprising a handle movable between a iirst and a second position wherein said contacts are, respectively, engaged `and disengageda torsion spring, means interconnecting said torsion spring to said handle for loading of said spring during initial movement of said handle from both of said iii-st and said second positions to the other `of said positions, releasahle latch means for restraining said movable contact while said spring is being loaded, means for releasing said latch means after said spring is loaded, and link means connecting said spring to said movable contact for snap-acting'movement thereof upon release of said latch means; an insulating sleeve, a reciprocable insulating rod means extending through said sleeve and interposed between said operating mechanism and said stationary contact; sm'd movable contact being positioned intermediate the ends of said rod means and mounted `thereto for movement in unison therewith; means extending through said rod means for conductively connecting said movable contact to an external circuit; said rod means being of a lesser diameter than said sleeve to provide an annular' space for the reception of an electric current arc drawn between said contacts; `said link means comprising a iirst arm mounted .to a stationary pivot, a second arm pivoted intermediate the ends thereof to said first arm; a pivotal arm and a moving pivotal connection to journal movement of the other end of said second arm.

2. A circuit internupter including a stationary contact, a movable Contact, and an operating mechanism means interconnecting said operating mechanism to said movable contact for moving said movable contact into and out of engagement with said stationary Contact; said operating mechanism comprising a handle movable betweenl a iirst and a second posit-ion wherein said contacts are, respectively, engaged and disengaged, `a torsion spring, means interconnecting said torsion spring to said handle for loading of said spring during initial movement of said handle from both of said 4first and said second positions to the other of said positions, releasable latch means for restraining said movable Contact while said spring is being loaded, means for releasing said latch means after said spning is loaded, and link means connecting said spring to said latch means; an insulating sleeve, a reciprocable movable contact for snap-acting movement thereof upon release of said insulating rod means extending through said sleeve and interposed between said operating mechanism and said stationary contact; said movable contact being positioned intermediate the ends of said rod means and mounted thereto for movement in unison therewith; means extending through said rod means for conductive-ly connecting said movable contact to an external circuit; said rod means being of a lesser diameter than said sleeve to provide an annular space for the reception of an electric current arc drawn between said contacts; said link means comprising a rst arm mounted to a stationary pivot, a second arm pivoted intermediate the ends thereof to said first arm; a pivotal connection between said rod and one end of said second arm and a moving pivotal connection to journal movement of the other end of said second arm; said moving pivotal connection including an elongated guide member extending at right angles to said stationary pivot; said other end of said second arm being movable along the longitudinal axis of said guide member.

3. A circuit internupter including a stationary contact, a movable contact, and an operating mechanism means interconnecting said operating mechanism to said movable contact for moving said movable contact into and out of engagement Iwith said stationary contact; said operating mechanism comprising a handle movable between a rst and a second position wherein said contacts are, respectively, engaged and disengaged, a torsion spring, means interconnecting said torsion spring to said handle for loading of said spring during initial movement of said handle from both of said iirst and said second positions to the other of said positions, releasable latch means for restraining said movable contact while said spring is being loaded, means for releasing said latch means after said spring is loaded, and link means connecting said spring to said movable contact for snap-acting movement thereof upon release of said latch means; an insulating sleeve, a reciprocable insulating rod means extending through said sleeve and interposed between said operating mechanism and said stationary contact; said movable Contact mounted thereto for movement in unison therewith; means extending through said rod means or conductiveiy connecting said movable contact to an external circuit; said rod means being of a lesser diameter than said sleeve to provide an annular space for the reception of an electric current arc drawn between said contacts; said handle being pivotable about an axis coinciding with the axis of said spring.

4. The circuit interruptor of claim 1 wherein said st-ationary contact comprises a single member having an opening therein; said movable contact being entered into said opening when said contacts are engaged, and being substantially included within the axial length dened by said stationary contact.

5. The circuit interrupter of claim 1, further including means cooperating with said link means to accurately tix the position of said movable Contact -in its engaged position.

6. The circuit internupter of claim l, wherein said handle being pivotable about an axis coincides with the axis of said spring.

7. The circuit interruptor of claim 1, further including a first arm, latch means, and means for releasing said latch means, also pivotable about said axis.

8. The circuit interrupter of claim 7, wherein said axis comprises a stationary pivot; a second arm pivoted intermediate th-e ends thereof -to said first arm; a pivotal connection between said rod and one end of said second arm and `a moving pivotal connection to journal movement of the other end of said second arm; said moving pivotal connection including an elongated guide member extending at right angles to said stationary pivot; said other end of said second arm being movable along the longitudinal axis of said guide member.

9. The circuit interruptor of claim 7; further including, a rst and second projection integral with said tirst arm and means for releasing said latch means respectively; said first and second projections engaging iirst and second ends of said spring; said latch means, carried by said Ifirst arm and operatively associated with said releasing means for nestraining movement of said rst arm for a predetermined interval; rotation of said means for releasing said latch means about said stationary pivot while said iirst arm is restrained angularly separating said iirst and second projections, thereby charging said spring.

References Cited in the ille of this patent UNITED STATES PATENTS 

1. A CIRCUIT INTERRUPTER INCLUDING A STATIONARY CONTACT, A MOVABLE CONTACT, AND AN OPERATING MECHANISM MEANS INTERCONNECTING SAID OPERATING MECHANISM TO SAID MOVABLE CONTACT FOR MOVING SAID MOVABLE CONTACT INTO AND OUT OF ENGAGEMENT WITH SAID STATIONARY CONTACT; SAID OPERATING MECHANISM COMPRISING A HANDLE MOVABLE BETWEEN A FIRST AND A SECOND POSITION WHEREIN SAID CONTACTS ARE, RESPECTIVELY, ENGAGED AND DISENGAGED, A TORSION SPRING, MEANS INTERCONNECTING SAID TORSION SPRING TO SAID HANDLE FOR LOADING OF SAID SPRING DURING INITIAL MOVEMENT OF SAID HANDLE FROM BOTH OF SAID FIRST AND SAID SECOND POSITIONS TO THE OTHER OF SAID POSITIONS, RELEASABLE LATCH MEANS FOR RESTRAINING SAID MOVABLE CONTACT WHILE SAID SPRING IS BEING LOADED, MEANS FOR RELEASING SAID LATCH MEANS AFTER SAID SPRING IS LOADED, AND LINK MEANS CONNECTING SAID SPRING TO SAID MOVABLE CONTACT FOR SNAP-ACTING MOVEMENT THEREOF UPON RELEASE OF SAID LATCH MEANS; AN INSULATING SLEEVE, A RECIPROCABLE INSULATING ROD MEANS EXTENDING THROUGH SAID SLEEVE AND INTERPOSED BETWEEN SAID OPERATING MECHANISM AND SAID STATIONARY CONTACT; SAID MOVABLE CONTACT BEING POSITIONED INTERMEDIATE THE ENDS OF SAID ROD MEANS AND MOUNTED THERETO FOR MOVEMENT IN UNISON THEREWITH; MEANS EXTENDING THROUGH SAID ROD MEANS FOR CONDUCTIVELY CONNECTING SAID MOVABLE CONTACT TO AN EXTERNAL CIRCUIT; SAID ROD MEANS BEING OF A LESSER DIAMETER THAN SAID SLEEVE TO PROVIDE AN ANNULAR SPACE FOR THE RECEPTION OF AN ELECTRIC CURRENT ARC DRAWN BETWEEN SAID CONTACTS; SAID LINK MEANS COMPRISING A FIRST ARM MOUNTED TO A STATIONARY PIVOT, A SECOND ARM PIVOTED INTERMEDIATE THE ENDS THEREOF TO SAID FIRST ARM; A PIVOTAL ARM AND A MOVING PIVOTAL CONNECTION TO JOURNAL MOVEMENT OF THE OTHER END OF SAID SECOND ARM. 